Photographic color correction using colored and uncolored couplers



United States. Patent PHOTOGRAPHIC COLOR CORRECTION USING COLORED AND UNCOLORED COUPLERS No Drawing. Application November 22, 1954,

Serial No. 470,499

14 Claims. (Cl. 96-9) This invention relates to color photography and'particularly to color correction by incorporating in a silver halide emulsion a mixture of colored and uncolored couplers.

It is known that colored photographic images may be formed by using a developer which produces a colored compound on development. The colored compound thus formed is deposited adjacent the silver grains of the silver image during development. It is also known that a colored image may be formed by adding to certain developing solutions or by incorporating in the silver halide emulsion a compound which couples during development with the oxidation product of the developing agent and forms a colored compound which is likewise adjacent the silver grains of the silver image during development. Such a compound which is employed in conjunction with the developing agent for the "silver andwhich couples with the oxidation product of the developing agent during development is referred to herein as a color forming compound or coupler.

In United States Patent No. 2,428,054, dated Sep tember 30, 1947, of P. W. Vittum et al., there is described a method for obtaining improved dye images by the use in the emulsion layer of a mixture of a colored coupler and a colorless coupler which produce dye images of the same hue upon coupling. Development of the exposed layer results in the color of the colored coupler being destroyed upon coupling, while at the same time the colorless coupler forms a dye image at the exposed regions. In this way, a masking effect is achieved whereby undesired absorption, for example, in the blue spectral region is cancelled out. However, it has been found that the choice of couplers is restricted and complete masking has not been possible. Also, the requirement of employing only those colored couplers which produce on development dyes of the same hue as the uncolored coupler seriously limits the application of this prior art process for many photographic materials and processes.

I have now found that by the use in silver halide emulsions of a combination of certain colored couplers, the dyes from which become soluble in the exposed areas on development and thereby permit complete removal by washing methods of the dye image thereof, with certain uncolored couplers that on development form insoluble dye images, some of the disadvantages of the prior art processes are overcome. Such combinations provide sharply defined dye images and excellent masking out of undesirable wave lengths. The effect in negative developmentis to obtain as a function of exposure a positive dye image from the colored coupler and a normal or negative image from, the uncolored coupler. This results in a color correction mask with a normal dye image. In a reversal process whereinthe exposed silver halide is developed with a silver forming developer and the re- ,sidual silver halide'is then developed with a color form- 70 2,808,329. 1C6 Patented Oct. 1, 195.7.

ing developer, the opposite relationship exists. The uncolored coupler forms a positive dye image and the colored coupler forms a negative dye image. The result is as before a color correction mask for the normal dye image. The choice of couplers determines the color of the positive image and also what wave lengths of light are transmitted through these images to the underlying silver halide emulsion layer or layers. Further advantages arise from the fact that more silver halide is required in my proposed system in order to produce the same amount of dye as is produced in the above-mentioned patent of P. W. Vittum et al. ,This kind of ad-. vantage can be better understood from. a consideration of the process of U. S. Patent No. 2,689,793, dated September 21, 1954, of W. R. Weller et al.

Increasing the amount of silver halide used increases. the emulsion speed and lowers the .graininess of the dye image. The invention is, therefore, particularly adaptable to color photographic elements employing a plurality of superimposed silver halide emulsion layers wherein at least one layer or, if desired, all the layers contains a combination of at least one colored coupler and at least one uncolored coupler. 7

It is, accordingly, an object of the invention to provide a new colorphotographic'element having a plurality of superimposed silver halide layers sensitized to different colors and wherein. atleast. one layer contains a combination of a colored coupler and an uncolored couplerc Another object is to provide a color photographic element of the above kind wherein color correction is attained by a new method of masking. Another object is to provide a process for preparing the said new element. Other objects will become apparent hereinafter.

In accordance with the invention, I prepare color photographic elements by coating in any order two or more differently sensitized silver halide emulsions, for example, sensitized to the blue, green and red, over one another and, if desired, separated by inert or colored gelatin layers, onto a suitable. photographic supportmaterial such as films or sheets of cellulose acetate, cellulose mixed esters, cellulose nitrate, cellulose ether, synthetic resin materials such as polyesters, polyamides, etc.,. paper materials, glass plates, and the like. The preferred photographic color element contains three differently sensitized silver halide emulsion layers in the order of a bottom red-sensitized layer next to the support, a middle green-sensitized layer and a top blue:sensitize d layer. While suitable combinations of the colored and uncolored. couplers may be incorporated in any one or allot these layers, a preferred form of my invention is to include a suitable yellow colored coupler, together with a. suitable uncolored couplerin the green-sensitized layer, a suitable magenta colored-coupler with an uncolored coupler in the blue-sensitive layer and a suitable orange colored coupler with an uncolored coupler in the red sensitized layer.

Suitable colored couplers which react with developers of the ph'enylene diamine type to give water-soluble dyes. include a wide variety of nondiffusing azo type yellow, orange and magentacolored couplers. Those which are particularly useful in this invention may be represented by the following generalformulas-L and OONHR;

t l 7 R2 wherein R1, R3 and R4 are simple or complex alkyl or aryl groups or combinations of these containing one or more solubilizing groups such as sulfo or carboxy groups, and R2 represents a ballasting group. A typical yellow colored coupler of structure I described in U. S. Patent No. 2,435,616, dated February 10, 1948, of P. W. Vitturn, is 1-p-sulfophenyl-3-methyl-4-p-laurylphenylazo-S-pyrazolone which coupler on incorporation into a silver halide emulsion, followed by exposure and development with a p-amino dirnethylaniline developing solution is converted in the exposed areas to a water-soluble, dit fusible azo methine dye which will wash out of the film. This soluble dye may be represented by the following structural formula:

CH3 NaOaSON on:

After fixing and the usual silver removal baths, a reversed yellow image of the unconverted yellow azo dye remains. Other structures of azo type colored couplers which react in similar manner are described in the following:

N=G-NHC O 1-pheny1-3- (3-sulfobenzamido) 4-(4-octadecy1oxyphenylazo)- 5-pyrnzolone 1pheny1-3- (Z-carboxybenzamido) 4- (4-dodecyloxypheuylazo) o-pyrazolone 1 (4-su1fophenyl) -3-Inethyl-{4- [4 (l-cert. buty1)phenoxy] pheny1azo}-5-pyrazo1one This compound can be prepared by the general procedure of above compound (2).

Typical compou-ndssof structure II include those such as:

(4) 1 hydroxy N [,8-(3-suIfobenzamido)ethyl]-4- (2-dodecyloxycarbonylphenylazo-2-naphthamide, wherein the R1 group is soar! and the R: group is QC OaCnHryll wherein n stands for normal chain.

(5) 1 hydroxy 4(2 dodecyloxycarbonylphenylazo- 3,'5'-di-carboxy-2-naphthamide, wherein the R1 group is doon and the R2 group is QC OiCnHzs-D.

(6) 1 hydroxy N [p (3,5 disulfobenzamido)- ethyl] 4 (2 dodecyloxycarbonylphenylazo) 2 naphthamide, wherein the R1 group is CH2CH2NHCO and the R2 group is azo) N [5 (3 sulfobenzamido)ethyII-Z-naphthamide, wherein the R1 group is SOaH and the R2 group is oa aHn-n (8) The sodium salt of l-hydroxy-4-(Z-dodecyloxycarbonylphenylazo)-2-(4-sulfonaphthanilide), wherein the R1 group is and-the R2 group is (9) 1 hydroxy 4 (2 amyloxycarbonyl) 3 naphthylazo) N [B (2 carboxybenzamido)ethyl]-2-naphthamide, wherein the R; group is nd the R2 group is (10) 1 hydroxy 4 [(2 dodec yloxycarbonyl) 3 na'p'hthylazoyN-(3-carboirypheny1) Z-napthamide, wherein the R1 group is and the R2 group is (5 i C rain-1 (11) 1 hydroxy N 3 [a (3,5 dicarboxyphe noxy) acetamidokthyl} 4 (3 dodecyloxycarbonyl 2'- naphthylazo)-2-naphtharnide, wherein the R1 group is COOH a'nd the R2 group is Cronin- 1 (12) 1 hydroxy N-[fi (3 canboxyphenylsulfoiiamido)ethyl] 4 4 (2 dodecyloxycarbonyl 3 with I thylazo-Z-naphtliamide, wherein the R1 group is anti the R1 grou is I OzCn u 13 '1 hydroxy N p oa'rboi'r'yethyi) 54 7 {-3 [a- (2,4 di tertiary amylphenoxy) ethoxyoarbonyl]; 2- nephthylaZQ-Z-naphthamide, wherein the R1 group is CH2CH2CO2H and the R2 group is and the R2 group is befitting-1100,1111

() 1 hydroxy N (3 carboxyphenyl) 4 {3--' [p1 2,4 di tertiaryamylpheiioxy)ethoxycarbonyl] 2 naphthylazo}-2-naphthaniide, wherein the R1 group is and the R2 group is (16) 1 hydroxy 4 "{3 [p 2,4 di tertiaryamylphenoxy)ethoxycarbony1] -'2--naphthy1azo} N [,8

(3-sulfobenzarnido)ethylfhZ-nephthmide, wherein the R1 group is -OH2CH2NHCO and the R2 group is oiontdm mQosfin-t aHn-t I (17) 1 hydroxy N -[)9 (2 carboxybenzamido) ethyl] 4 (2 dodecycloxycarbonyl 3 naphthylazo) 2-naphthamide, wherein the R1 group is l )0011 and the R2 group is O2C12 tn-i1 (18;) 1 Hydroxy N 8 (2 f carboxybenzamido ethyl] 4- {2 {,8 [fl (fl-ethoxyethoxy) e'thoxy] ethoxycarbonyl} naphthylazo} 2 naphthamide, wherein the R1 group is 1 30011 and the Rz groupis Q QgH4OCgfiAOCRH4O 01111 (19) 1 hydroxy N [,9 (2 carboxybenzamido) ethyl] 4 {2 [/8 -'-eth x-yethoxy)-ethoxycarbony1] 3-naphthylazo}-2-naphth2imide, wherein the R1 group is -o'moHiNHooQ 7 V oon i and the R2 group is ororn ommoolrm 1 hydroxy N (3 carboxyphenyl) 4 -(4- dodecyloxyphenylazo) 2 naphtharnide, wherein the R1 group is and the R2 group is (21) 1 hydroxy N; (5 carboxy-2-chlorophenyl)- 4 (6 palmitamido 2 naphthylazo)-2-naphthamide, wherein the R1 group is The general method of preparing the compounds of structure II is illustrated by the following examples. First the solubilizing group is attached to coupler molecule as described in Examples -1-'-3.

Example I COaCsH HgNOHaCHaNHI O ONHCHzCH=NH1 Phenyl-l-hydroxy-Z-naphthoate is added to an excess of ethylene diamine and warmed on a steam bath. The excess ethylene diamine is removed by vacuum distillation and the residue recrystallized from acetonitrile. The naphthol product (A) is then mixed with phthalic anhydride in acetonitrile and the mixture heated on the steam bath. The product OONHCHzGHzNHGO-Q COOH crystallizes from solution and is collected.v

Example 2 OH cool CONHCHzCHzNH:

G ONHOHzGErNH: 010 0- N H: CaHnOH Two equivalents of the naphthol product (A) of Example 1 were dissolved in dioxane and one equivalent of the-acid chloride dissolved in dioxane added. The precipitated amine hydrochloride is separated by filtration. The filtrate is drowned in water and the precipitate collected. This is then refluxed in a 50-50 water and alcohol solution, the excess alcohol removed and the aqueous residue filtered. The filtrate is chilled and the product collected which has the structure:

CONHCHaC-HzNHG 0Q sour Example 3 OH SOsH oonucmonmacoQ The procedure for obtaining this product is the same as described in Example 2.

Secondly, the compounds furnishing the ballast group R2 are prepared, for example, as described in the following example:

3-amino-2-naphthoic acid is dissolved in an excess of n-amyl alcohol and dry hydrogen chloride is passed into the mixture. After refluxing several .hours, the excess alcohol is removed by vacuum distillation and the residue stirred in a sodium carbonate'sol-ution. The product is collected on a filter and dried.

(b) n-Dodecyl alcohol was substituted for the n-amyl alcohol in above (a) to give the corresponding dodecyl derivative.

(0) 2,4-diamyl-;S-hydroxyethoxybenzene was substituted for the n-amyl alcohol in above (a) to give the corresponding derivative.

. (d) Z-aminobenzoic acid was substituted for the 3 amino-Z-naphthoic acid in above (a) to give the compound, Z-amino-dodecylbenzoate.

Thirdly, the compounds furnishing the ballast group, prepared according to Example 4, are diazotized and then coupled in a basic medium such as pyridine, sodium hydroxide or acetic acid-i-sodium acetate with the solubilized compounds prepared according to above Examples 1-3, and the azo dyes which form are collected and purified.

Suitable uncolored non-diffusing couplers for use in my invention include any of those described in United States Patent No. 2,298,443, dated October 13, 1942, of A. Weissberger.

The following examples illustrate how the colored and uncolored couplers may be employed in the prac- -Example 4 tice of my invention to p'rep'are'color photographic elements having improved masking properties;

Example 4 parts by weight of an uncolored coupler, N-(pbenzoylacetaminobenzeiiesulfonyl)-N-( phenylpropyl)- p-toluidine, dissolved in 8 parts of di-n-butyl phthalate were dispersed in 17 parts by weight of a aqueous gelatin solution. A solution in'ethanol containing sodium carbonate of 1 part by weight of acolored coupler, l-hydr'0xy-4- (2-amyloxycarbonyl-3 -naphthylazo) -N- [,6- 3-su=lfobenzarnido) ethylJ-2-naphthamide, was added to this dispersion and this was followed by the addition of 14 parts by weight of a silver bromoiodide emulsion. Coating and processing was then carried out in a normal manner.

The developer composition was as follows:

Grams Sodium hexametaphosphate 1.0 Z-amino-S-diethylamino toluene hydrochloride 2.0 Sodium sulfite 2.0 Potassium bromide 2.0 Sodium carbonate 20.0 Water to make up a volume of 1000 cc.

The processing was as follows: v Developing time 7 min at 70 F. Rinsing time 5 sec.

Fixing time 30 sec. Washing time 3 min. Bleaching time 30 sec. in 50 g. of

potassium ferricyanide plus 20 g. of

potassium bromide v W per liter of water. Rinsing time..' 10 sec. Fixing time 30sec. Washing time 3 min.

The process sample was then dried. Sensitometric tests indicated that this particular sample actually showed slight overcorrection of color, but subsequent samples were prepared of proper color correction by varying the ratio of colored to uncolored coupler.

Example 6 This example was carried out the same as Example 5, except that the uncolored coupler, 1-hydroXy-2-[8(2',4'- di-tert. amylphenoxy)-n-butyl]-naphthamide (prepared according to U. S. Patent No. 2,474,293, dated June 28, 1949, of A. Weissberger et al.), which reacts with N- ethyl-N-(B-sulfonamidoethyl)*3-methyl-4-aminoaniline to produce a cyan dye having an appreciable amount of green and blue absorption, was substituted for the uncolored coupler employed in Example 5. The emulsion was coated and processed as in Example 5. Sensitometric tests indicated that this particular sample showed excellent color correction.

Example 7 This example illustrates a coating made with a solvent type of dispersion. An uncolored coupler, 1- (2',4',6-t'richlorophenyl) -3- 3 "-=(2"',4'-di-te(rt. amylphenoxy-acet. amido)-benzamido]-5-pyrazolone (prepared according to U. S. Patent No. 2,600,788, dated June 17, 1952, of A. Loriaet al.), which reacts with N-ethyl-N-QEi-sulfonamL doethyl)-3-methyl-4-aminoaniline to produce a magenta dye, and a colored coupler, 1-phenyl-3-(2-carboxybenzamido)-4-(4edodecyloxy-phenylazo)-5-pyrazolone, which reacts to produce a soluble dye, were dispersed in N-nbutylacetanilide and this dispersion was then added'to a silver halide emulsion.

The coating was processed as in above Example 5. Sensitometric tests of the sample showed excellent color correction.

Example 8 This examplewas carried out the same as Exam ner,

scape-mag the u earned coupler. was "first dis'peised iii the Nfn-butylacetanilide and to this dispersion was added the ammonium salt of 1-phenyl-3-(Z-carboxybenZamido) l (4i dodeeyloxyphenylaio) 5-pyrazolone.

' V V V Examp'le9 rmskia'mpa was darne out the same as n'x'a'm e s, exceptflthat the trimethylbenzyl ammonium salt of 1'- phenyl-3 (2 carboxybenzairiido) 4-(4-dodecyl0x'yphen ylaZo)-5-pyra'zolone was employed instead of the free aztld; V V I l V i Example 10 11111118 example a multilayer film was prepared as" follows: (1) a mixture of 4'-(4-ter-t. butylphenoxy) -1-hydroxy-4-phenylazo-2-naphthanilide, an orange colored coupler yielding a cyan dye, and 1-hydroxy2-[6(2',4'-ditert. amylphenoxy)-n-butyl] -naphthamide, an uncolored coupler yielding a cyan dye, dissolved in tricresylphosphate was added to the red-sensitive silver halide emulsion and coated as the bottom layer; (2) a mixtureof l(2,4,6'- trichlorophenyl) -3 [3" (2",4-diamyl phenoxyacetamide) benzamidoJ -4 (pmethoxyphenylazo)-5 'pyrazolone, a yellow-colored coupler yielding a magenta dye, and 1- (2',4f,6f-trichlorophenyl)-3- ['3f-(2f,4"' di-tert. amyl phenoxyacetamido) -benzamido]-5-pyrazol0ne, an uncoloredcoupler yielding a magenta dye, dissolved in tricresyl phosphate, was added to the green-sensitive silver halide emulsion and coated as the middle layer, (3) a mixture of N-(p-benzoylacetaminobenzenesulfonyl) -N- (y-phenylpropyl)-p-toluidine, an uncolored coupler yielding a yellow dye and 1-hydroxy-4-(2-amyloxycarbonyl-3- naphthylazo')'-N- [fl(2-carboxybenzamido) ethyl] Z-naphthamide, a magenta-colored coupler yielding a soluble dye, dissolvedin di-n-butyl-phthalate, was added to an unsensitized silver halide emulsion and coated over a vellnw filterlayer. 1 I I -This coated film was processed as in ExampleS, except that the bleaching time was extended to 8 minutes and the fixing times were extended to 5 minutes.

;The sensitometric; tests showed excellent color correctiori in the individual layers and in the composite film.

By proceeding in accordance with the above'Examples 5- -;l0,--other'silver halide dispersions containing one or moreof the mentioned colored and uncolored color-forming couplers can be prepared and these dispersions'may then be coated-and processed into color corrected layers. As previously indicated, variously sensitized layers can be superimposed and by proper choice of colored and uncolored couplers in the respective layers, and sequence of layers, it is possible to produce by my invention, accurate CONE-R1 wherein R1, R3 and R4 each represents a member selected from the group consisting of an alkyl group and an aryl group, said group having at least one solubilizing group attached thereto selected from the group consisting of a carboxy group, a sulfo group, an alkali metal carboxy group, an alkali metal sulfo group, an ammonium carboxy group and an ammonium sulfo group, and R2 represents an aromatic radical having attached thereto an alkyl group of from 4 to 15 carbon atoms, which comprises exposing said element and developing it to form color images from said uncolored and said colored colorforming couplers in the exposed portions and simultaneously to split said colored color former at the azo group, thus forming a soluble dye which is removed from the emulsion layer, leaving the uncoupled portion of said colored color former in the said emulsion layer as a mask image.

2. The method set forth in claim l in which the said colored color former contains at least one carboxyl group.

3. The method set forth in claim 1 in which the said colored color-forming coupler contains at least one sulfonic acid group.

1 4. The method set forth in claim 1 in which the said colored color-forming coupler containing at least one carboxyl group is in the form of an alkali metal salt thereof.

5. The method set forth in claim 1 in which the said colored color-forming coupler containing at least one sulfonic acid group is in the form of an alkali metal salt thereof.

6. The method set forth in claim 1 in which the said colored color-forming coupler containing a carboxyl group is in the form of an ammonium salt thereof.

'7. The method set forth in claim 1 in which the said uncolored color-forming coupler is N-(p-benzoylacetaminobenzenesulfonyl) N ('y phenylpropyl) p toluidine and the said colored color-forming coupler is the sodium salt of l hydroxy 4 (2 amyloxycarbonyl- 3 naphthylazo) N (3 sulfobenzamido) ethyl]- Z-naphthamide.

8. The method set forth in claim 1 in which the said uncolored color forming coupler is 1 -,hydroxy 2- [62',4' di tert. amylphenoxy) n butyl] naphthamide and the said colored color-forming coupler is the sodium salt of 1 hydroxy 4 (2 amyloxycarbonyl 3 naphthylazo) 1 N [B (3 sulfobenzamido) ethyl] 2 naphthamide.

9. The method set forth in claim 1 in which the said uncolored color-forming coupler is l-(2',4',6'-tricl1lorophenyl) -3- [3 (2"',4-di-tert. amylphenoxyacetamido) benzarhidol-Spyrazolone and the said colored color-formr ing coupler is the sodium salt of l-phenyl-3-(2-carboxybenzamido) -4- 4-dodecyloxyphenylazo) -5 -pyrazolone.

l() The method set forth in claim 1 in which the said uncolored color-forming coupler is l-(2,4,6'-trichlorophenyl -3- [3"- 2,4di-tert. amylphenoxyacetamido) benzamidol-S-pyrazolone and the said colored color-forming coupler is the ammonium salt of l-phenyLB-(Z-carboxybenzamido) 4 (4 dodecyloxyphenylazo)-5-pyrazolone.

llTThe method set forth in claim 1 in which the said uncolored color-forming coupler is l(2',4',6'-trichlorophenyl)-3-[3"-(2,4'di-tert. amido)-benzamido]-5-pyrazolone and the said colored amplphenoxy-acetcolor-forming coupler is the trimethylbenzyl ammonium salt of l-phenyl-3-(Z-carboxybenzamido)-4-(4dodecyloxyphenylazo -5-pyraz0lone.

12. The method of producing a masking image in a three-layer photographic element, said layers being silver? 12 ing coupler selected from the groups consisting of those represented by the following general formulas:

and

wherein R1, R3 and R4 each represents a member selected from the group consisting of an alkyl group and an aryl group, said group having at least one solubilizing group attached thereto selected from the group consisting of a carboxy group, a sulfo group, an alkali metal carboxy group, an alkali metal sulfo group, an ammonium carboxy group and an ammonium sulfo group, and R2 epresents an aromatic radical containing an alkyl group of from 4 to 15 carbon atoms, which comprises exposing said element and developing it with a primary aromatic amine developing agent to form color images in the bluesensitized layer from said uncolored and said colored color-forming couplers in the exposed portions and simultaneously to split said colored color former at the azo group, thus forming a soluble dye which is removed from the blue-sensitized emulsion layer, leaving the uncoupled portion of said colored color-former as a mask in the said blue-sensitized emulsion layer.

13. A photographic element comprising a support having thereon at least one silver halide emulsion layer which contains at least one uncolored color-forming coupler which is reactive with the oxidation product of a primary aromatic amine developing agent to form a non-diffusible dye in the said layer and which further contains at least one colored color-forming coupler selected from the groups consisting of those represented by the following general formulas:

' wherein R1, R3 and R4 each represents a member selected from the group consisting of an alkyl group and an aryl group, said group having at least one solubilizing group attached thereto selected from the group consisting of a carboxy group, a sulfo group, an alkali metal carboxy group, an alkali metal sulfo group, an ammonium carboxy group and an ammonium sulfo group, and R2 represents an aromatic radical containing an alkyl group of from 4 to l5 carbon atoms.

14. The method set forth in claim 12 in which the said uncolored color-forming coupler is N-(p-benzoylacetaminobenzenesulfonyl) N (q-phenylpropyl) p toluidine and the said colored color-forming coupler is the sodium salt of l-hydroxy-4 (2-amyloxycarbonyl)-3-naphthylazo-N- [u- 3-sulfobenzamido) ethyl] -2-naphthamide.

2,435,616 Vittum et al. Feb. 10, 1948 Vittum et al. Sept. 30, 1947 

1. THE METHOD OF PRODUCING A MASKING IMAGE IN A MULTILAYER PHOTOGRAPHIC ELEMENT, SAID LAYERS BEING SILVER HALIDE EMULSION LAYERS, AND WHEREIN AT LEAST ONE OF SAID LAYERS CONTAINS AT LEAST ONE UNCOLORED COLOR-FORMING COUPLER WHICH IS REACTIVE WITH AN OXIDATION PRODUCT OF A PRIMARY AROMATIC AMINE DEVELOPING AGENT TO FORM A NONDIFFUSIBLE DYE IN TH SAID LAYER AND FURTHER CONTAINS AT LEAST ONE COLORED COLOR-FORMING COUPLER SELECTED FROM THE GROUP CONSISTING OF THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULAS: 